The disinfection of drinking water was a major public health achievement of the 20th century; however, an unintended consequence is the generation of toxic disinfection by-products (DBPs). The Principal Investigator requests funding for a recurring Gordon Research Conference (GRC), entitled Drinking Water Disinfection By-Products: Charting the Horizons of Interdisciplinary Research and Application in Water Disinfection, By-Products, Water Reuse, and Public Health. A Gordon Research Seminar (GRS) managed by postdoctoral fellows and graduate students will precede the GRC by 1 day. The topics covered by this GRC/GRS incorporate the mission of the National Institute of Environmental Health Sciences which is to discover how the environment affects people in order to promote healthier lives. This conference will include the latest research on DBP formation, occurrence, toxicity, exposure, and epidemiology with the goal of facilitating dialog between chemists, toxicologists, epidemiologists, and engineers. With the advent of climate change-associated droughts, source water degradation is a high concern in that the chemical spectrum of DBPs is changing and these emerging DBPs appear to be more toxic. This GRC/GRS is unique from past GRC meetings because of its focus on public health and environmental risks posed by emerging DBPs generated by the use degraded source waters, wastewater reuse, and desalination. The format of the GRC/GRS is especially conducive in initiating collaborative studies on the epidemiology, toxicology, exposure, occurrence, and formation of these novel DBP classes. A goal of the GRC/GRS is to aid in the establishment of interdisciplinary teams of academic scientists and engineers with industry scientists to develop new solutions and alternative practices to address these DBP issues and to protect the environment and the public health.